Location, abundance, and morphology of gill chloride cells were quantified during changes in osmoregulatory physiology accompanying early development in American shad, Alosa sapidissima. During the larval-juvenile transition of shad, gill chloride cells increased 3.5-fold in abundance coincident with gill formation, increased seawater tolerance, and increased Na(+),K(+)-ATPase activity. Chlorid...

It has recently been shown that a few fish species, including American shad (Alosa sapidissima; Clupeiformes), are able to detect sound up to 180 kHz, an ability not found in most other fishes. Initially, it was proposed that ultrasound detection in shad involves the auditory bullae, swim bladder extensions found in all members of the Clupeiformes. However, while all clupeiformes have bullae, n...

A major challenge in conservation biology is the need to broadly prioritize conservation efforts when demographic data are limited. One method to address this challenge is to use population genetic data to define groups of populations linked by migration and then use demographic information from monitored populations to draw inferences about the status of unmonitored populations within those gr...

—We present a population dynamics model based on the life history of anadromous Alosa. The model is built around a catch-at-age array to which we have added an additional dimension to include previous spawning history. The previous spawning history determines the number of times that a fish is exposed to riverine impacts that contribute to overall mortality rates. The model is designed to incor...

Contemporary insights from evolutionary ecology suggest that population divergence in ecologically important traits within predators can generate diversifying ecological selection on local community structure. Many studies acknowledging these effects of intraspecific variation assume that local populations are situated in communities that are unconnected to similar communities within a shared r...

The trophic linkage between yellow perch Perca flavescens and two exotic prey items, alewife Alosa pseudoharengus and round goby Neogobius melanostomus, was investigated in the extreme southern area of Lake Michigan during the summer of 2002. Yellow perch 100mm total length, LT (n1⁄4 1293) exhibited size selective feeding, with 148 fish containing round gobies and 120 fish containing alewives. ...